The energy consumption of electrical and non-electrical loads, for example lighting devices, heating systems, air-conditioning units etc., is often registered (measured) in order to be able to invoice the costs in a manner dependent on consumption. In an analogous manner to a water meter which registers a quantity of water consumed, electricity meters are used to register the energy consumption of electrical loads and measuring units for a quantity of fuel (for example gas meters) are used to register the energy consumption of combustion devices. In the course of increased energy costs and a heightened environmental awareness, there is also often the desire in hotels, motels and similar facilities to register the consumption of resources (in particular the consumption of electrical energy) separately for each room or each suite and thus for each guest and to charge the customer (guest) separately. In this case, different “bonus schemes” may also be offered to the guests, for example in such a manner that, when a particular threshold value for the energy consumption is undershot, the guest is awarded a bonus or is promised some other benefit.
It has been found that it is very complicated to register the energy consumption separately for each guest or each room (suite) in a hotel or a similar facility because a separate meter, that is to say a separate measuring device, must be used for each point of consumption or part of a building (for example a room), this measuring device also having to be equipped for data transmission of the measured consumption value to a control center (in this case: the hotel reception).